String Column Aggregation Will Stops Working Elasticsearch-2.3.2

Elasticsearch version: 2.3.2

JVM version: 1.8

OS version: Cent OS

Description of the problem including expected versus actual behavior AND Steps to reproduce:

actually we have one large application and in that the indexing always
going on around min 500-1000 logs per second, and we have our defined
syntax for users to execute searching in elasticsearch.

But now we have one biggest issue after elastic version 2.3.2 that 

while indexing is going on and our user try to get aggregation on data
like sum, min, max etc.. on that time customer doesn't know that the
column is string or numeric so. Elasticsearch throws Error
(SERVER_ERROR) that need numeric field but found string field.

In this case Elasticsearch is right and scenario is perfect but after
this happens more then two times Elasticsearch stop working It's not
even responding in any plugin. It's also not even give status by
http://localhost:9200 so Please resolve my problem and reply me as soon
as possible.

We have very big work with Elasticsearch and then we stuck over here.

Check your ES logs, there should be something in there.

Also what monitoring do you have in place, ie Marvel?